This invention relates generally to dynamometers for absorption of the rotary output of a motor, and more particularly to a diagnostic dynamometer system for rotary blade-type or rotary motor driven lawn mowers.
It is well-known that, during the life of the motor of a machine such as a lawn mower, the rotary power output of such a motor will vary and may deteriorate based upon wear and environmental conditions. Although many of the worn components and deteriorated conditions may easily be repaired by conventional methods, procedures and replacement parts, the motor may typically only be operated, observed and adjusted in a "no-load situation" unless the motor is removed from the lawn mower deck to a test stand. However, many operating defects are only incurred under a partial or full load condition of such a motor.
Many systems have been developed which will apply a load to the motor of a machine such as the dynamometer for automobiles which will apply controlled loads to the drive wheels of such a vehicle. This loading is important for diagnosing operating defects, locating and replacing worn components and correcting mis-adjustments which might be unobservable during the normal operation of the vehicle over the road or in a static "no load"situation. With respect to lawn mowers, then, particularly the rotary blade-type, the only effective way known to applicant to load the motor of such lawn mowers in order to at least observe functional mis-adjustments and defects short of motor removal to a test stand is to actually run the mower through heavy grass or other heavy ground cover. This loading is applied to the motor via the grass cutting process to the rotating blade of such mowers.
Certain motors are equipped with a separate power takeoff which may be interengaged by a separate power absorption system. This power take-off accessory does provide a convenient means for applying a load to the motor in a controlled environment. However, the majority of the smaller less sophisticated mowers and equipment, as well as small diesel powered mowers, do not include any such power takeoffs.
In order to get any semblance of continuous loading on rotary mowers, then, the mower must be operationally loaded by continually moving the mower through heavy grass or ground cover. This presents the very practical problem of observing, diagnosing, adjusting, and so forth, a moving mower in the field, a difficult task at best.
The present invention provides a dynamometer system upon which such rotary blade-type lawn mowers may be placed, interengaged thereto, and secured thereon, after which the motor of the mower may be operated and observed, adjusted and repaired. A dynamometer connected beneath the support frame for the mower includes an input shaft which has connected thereto a blade engaging crossbar. Thus, by adjusting the power absorption controls related to the dynamometer, a variable load may be placed on the motor of the mower on a selectable steady state basis so that adjustments, repairs and observations may be made in this controlled situation, usually in a shop.